Development of an SNP-based high-density linkage map and QTL analysis for bruchid (Callosobruchus maculatus F.) resistance in black gram (Vigna mungo (L.) Hepper)

Prakit Somta,Chutintorn Yundaeng,Xingxing Yuan,Tarika Yimram,Xin Chen,Norihiko Tomooka,Jingbin Chen

doi:10.1038/s41598-019-40669-5

Abstract

Black gram (Vigna mungo var. mungo) is an important pulse crop in Asia. The cowpea weevil (Callosobruchus maculatus) is a stored-seed insect pest (seed weevil/bruchid) that causes serious postharvest losses in pulse crops, including black gram. In this study, we constructed a high-density linkage map for black gram and identified quantitative trait loci (QTLs) for C. maculatus resistance. A recombinant inbred line (RIL) population of 150 lines from a cross between BC48 [cultivated black gram (var. mungo); bruchid-susceptible] and TC2210 [wild black gram (var. silvestris); bruchid-resistant] were used to construct a linkage map of 3,675 SNP markers from specific-locus amplified fragment sequencing. The map comprised 11 linkage groups spanning 1,588.7 cM with an average distance between adjacent markers of 0.57 cM. Seeds of the RIL population grown in 2016 and 2017 were evaluated for C. maculatus resistance through two traits; the percentage of damaged seeds (PDS) and infestation severity progress (AUDPS). Inclusive composite interval mapping identified three QTLs each for PDS and AUDPS. Two QTLs, qVmunBr6.1 and qVmunBr6.2, mapped about 10 cM apart on linkage group 6 were common between PDS and AUDPS. Comparative genome analysis revealed that qVmunBr6.1 and qVmunBr6.2 are new loci for C. maculatus resistance in Vigna species and that genes encoding a lectin receptor kinase and chitinase are candidates for qVmunBr6.2. The high-density linkage map constructed and QTLs for bruchid resistance identified in this study will be useful for molecular breeding of black gram.

Highlights

Black gram (Vigna mungo (L.) Hepper) is an important legume crop of Asia
Compared with cultivated black gram, wild black gram shows a lower percentage of adult emergence (PAE), lower percentage of damaged seeds (PDS), and longer developmental period (DP) for C. maculatus[8]
Based on PAE evaluation, it was reported that the resistance to C. maculatus in V. mungo var. silvestris is controlled by two dominant duplicate genes, designated Cmr[1] and Cmr[26]

Summary

Introduction

Black gram (Vigna mungo (L.) Hepper) is an important legume crop of Asia. The two most important and damaging bruchid species for Vigna crops are the cowpea weevil (Callosobruchus maculatus L.) and azuki bean weevil (Callosobruchus chinensis F.)[1]. These two bruchid species are widely distributed across most continents due to international seed trading. Based on PAE evaluation, it was reported that the resistance to C. maculatus in V. mungo var. In this paper we report the development of a high-density linkage map for black gram using the SLAF-seq technique and the identification of QTLs controlling seed resistance to C. maculatus

Methods

Results

Conclusion